feat(vm): add support for virtiofs

[felinira]

This adds virtiofs support for virtual machines.

Usage:

resource "proxmox_virtual_environment_vm" "test_vm1" {
    /* ... */

    virtiofs {
	    dir_id = "test"
	    cache = "always"
	    direct_io = true
	    expose_acl = false
	    expose_xattr = false
    }
}

Contributor's Note

• I have added / updated documentation in /docs for any user-facing features or additions.
• I have added / updated acceptance tests in /fwprovider/tests for any new or updated resources / data sources.
• I have ran make example to verify that the change works as expected.

Proof of Work

Community Note

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Relates #1892 - directory mapping creation not yet implemented
Relates #1902 - acceptance test is commented out and requires #1902 as well

[bpg]

Hey @felinira 👋🏼
Thank you so much for adding this feature (and upcoming #1902 😉)

I have a few minor comments, but overall it looks great, solid work!

[bpg]

LGTM! 🚀